The cupcake craze is merging with the social media phenomenon, and the result is: cupcake trucks. Most major cities have these vendors, who rely on Facebook and Twitter to connect with customers.

In Denver, Sean Moore is known as "the cupcake guy." Each morning he loads up a 1969 Ford Vanette with sugary cakes made at a bakery he co-owns with his wife, Denon. Then Moore bounces over Denver's streets looking for customers.

Once he finds a good parking spot, near active businesses with a lot of people walking by, Moore sets his cupcakes on the counter and opens for business.

"Then I pull out my computer and basically link up with all my social networks and let them know where I'm at and how long I'll be here," he says.

Within just a few minutes, customers are responding online, either praising that he's nearby that day or cursing that he's too far for them to travel. During a recent stop in Denver's Highlands neighborhood, John Skrabec was one of the lucky ones.

"I work around the corner," he says. "I'm always on Facebook because I use social media for my business -- real estate."

The Denver Cupcake Truck sells dozens of cakes every day for $2.75 each. The goal is for the truck to bring in $1,000 a day to supplement the bakery.

To make that happen and to ensure their $25,000 investment in the truck pays off, the Moores have turned to social media. It's much cheaper than traditional advertising.

But the benefits are worth it, Denon says. The truck has boosted business at their bakery, and she says social media is good for market research. Customers suggest places to park the truck, and the Moores always have new flavor ideas.